Connecticut’s public schools — especially in urban districts like New Haven — are $1.5 billion underfunded every year, a state advocacy group reported Wednesday.

Two weeks after Governor M. Jodi Rell pledged an additional $3.4 billion in funding for state schools over the next five years, the Connecticut Coalition for Justice in Education Funding released its proposal for improving the state’s schools. The coalition, backed by the Yale Law School’s Education Adequacy Project, said Rell’s plan is a step in the right direction, but the fundamental framework of the state’s education funding system must be changed in order to fully provide schools with the resources they need.

Dianne Kaplan deVries, the project director of CCJEF, said the current funding formula bases costs on school districts’ past expenditures, not their current or future needs. Also, districts with large numbers of English-as-a-second-language students, special education students or students from low-income households often have to rely on high property taxes to cover costs, since the state funding does not take into account the special needs of individual students, she said.

While students from Connecticut’s wealthier towns frequently go out-of-state to college and do not return due to the state’s sluggish job market, deVries said, the students that are left have typically received subpar educations and then have trouble after high school.

“We have businesses across the state saying, ‘We can’t find capable entry-level workers,’” she said. “The youth that are staying are those that are basically unemployable because our schools are failing them. These are not the kids that come to school having gone to Europe in the summer … these are the kids that are really very dependent upon the schools to lift them up to do better than the previous generation.”

While Rell’s education funding increase attracted lavish praise from Democrats and Republicans alike, the state must push further in investing in schools, deVries said. The gap between Rell’s proposal — at its highest level of funding five years from now — and CCJEF’s is $1.4 billion, she said.

“[Rell is] a brave gal to have done this,” deVries said. “She opened the door and said, ‘Now it’s time to work on fixing this problem.’ … While this is a big step forward, it just wasn’t quite as progressive as it needs to be if it’s going to make a dent.”

Rell spokesman Rich Harris said the governor agrees that the subject of education funding deserves serious debate within the state.

“Governor Rell’s budget speech laid out exactly why we need to change our education funding system, including what the costs will be if we fail to act, and she recommended a way to pay for it,” Harris said. “She welcomes input from all of the concerned parties as this discussion moves ahead. It’s clearly a discussion that has to be had.”

Thirteen Yale Law School students who work on the school’s Education Adequacy Project — which represents CCJEF — support the advocacy group with legal assistance and helped prepare Wednesday’s proposal. Wally Adeyemo LAW ’08, the spokesman for the clinic, said the state needs to do more to provide students in New Haven and Hartford, as well as suburban and rural towns, with an education that will prepare them well for the future. It is constitutionally incumbent upon the state to do so, he said.

CCJEF, a bipartisan coalition of towns, boards of education, education associations, advocacy groups, unions, parents and others, was formed in 2004. Represented by the Yale clinic, the organization filed suit against the state in 2005, challenging the adequacy and equity of the education funding formula. That case, CCJEF v. Rell, is still pending.